Door closer



E. BILLETER Feb. 8, 1955 DOOR CLOSER 2 Sheets-Sheet Filed April 24, 1950a 5 z w E Feb. 8, 1955 BILLETER DOOR CLOSER Filed April 24, 1950 2Sheets-Sheet 2 United States Patent DOOR CLOSER Ernst Billeter,Kusnacht, near Zurich, Switzerland Application April 24, 1950, SerialNo. 157,664 Claims priority, application Switzerland April 28, 1949 3Claims. (Cl. 1659) The present invention relates to door closers andmore particularly to door closers of the hydraulically operated typecomprising a closing spring, such as are described in my earlierapplication Ser. No. 42,700, filed August 5, 1948, now Patent No.2,522,252, issued September 12, 1950, and Swiss Patent No. 262,506.

According to my present invention, the door closer comprises a hydrauliccheck operating to additionally retard the door closing movement withina certain angle of aperture of the door.

One form of my present invention is illustrated in the accompanyingdrawings in which Figs. 1-5 show the check in longitudinal section indiiferent working positions,

Fig. 6 shows a section on the line VI-VI of Fig. 1, and

Fig. 7 a vertical longitudinal section through the check.

Numeral 1 designates a check cylinder in which a check piston 2 ismovable. A crank axle 3 projects through the wall of the check cylinder,being disposed at right angles to the cylinder axis and carrying incylinder 1 an arm 4 provided with a crank pin which is engaged by apiston rod 5. The latter, as known in the art, is pivoted to the piston2 which, therefore, is moved in cylinder 1 on rotating the axle 3. Inpiston 2, further, there is inserted a check valve comprising aball 7movable in a duct 6 and adapted for co-operationwith a seat 8 and a stop9.

In the sliding face of piston 2 is provided a longitudinal groove 10 ofrectangular cross-section (Fig. 6). Two return conduits 11 and 12 withtheir two ends 11a, 12a and 11b, 12b open to the inside space ofcylinder 1 which through piston 2 is subdivided into a forward chamber13 and a rear chamber 14 respectively. A closing throttle 15 is providedin the return duct 11, and an additional throttle 16 in the return duct12. By screwingthe throttle elements 15, 16 in or out, the passagecross-sections of the respective ducts 11 and 12 may be reduced orenlarged respectively. The throttle elements always are so adjusted thatthe throttling action of element 16 is more pronounced than that ofelement 15.

On cylinder 1 is provided an override valve (Figs. 1-5) comprising alongitudinal bore 17 which opens into the two cylinder chambers 13 and14, and a valve plate 18 which opposes the flow of checking liquidthrough the said bore. The said plate 18 is loaded by a spring 21a whichis adjustable by means of a screw plug 21. A longitudinal groove 19 isprovided in the cylinder inside wall adjacent duct-end 12b. and anotherlongitudinal groove. 20 on the side opposite the ends of the ducts 11and 12. The groove 20 is somewhat longer than the check piston 2.

As shown in Fig. 7, an arm 22 forming a part of an elbow-joint linkageof well known construction, which is connected to the lintel of thedoor, at one end is pinned to the free end of crank-axle 3. The checkcylinder 1, however, is rigidly secured to the door. The cylinder 1carries a spring chamber 26 in which is disposed a closing spring 27which at one end is secured to the chamber 26 and at the other end tothe hub 29 of a spur gear 290 fixed on a sleeve 28 which is co-axialwith the crank axle 3 and freely rotatable in chamber 26, the spur gear29a engaging a pawl 30 which is carried by the arm 22.

The operation of the closer otherwise is as follows. Let it be assumedthat the door is in an opening position in which the check componentsoccupy the position shown in Fig. 1. The checking liquid is oil forexample.

Under the action of the closing spring 27, the crank axle 3 is rotatedby way of the parts 29, 30 and 22, whereby the piston 2 is moved to theright, as shown in Fig. 1. With the check valve 69 closed, oil is movedout of the cylinder chamber 14. The said oil flows through the returnduct 11, the piston groove 10 and the groove 19 into the cylinderchamber 13. A relatively small portion flows through the duct 12 intothe said chamber 13. The closing movement, therefore, is checked more orless in dependency on the setting of the throttle elements 15, 16. When,however, a certain reduced door opening angle has been reached, i. e.when the check components occupy the position shown in Fig. 2, thepiston 2 interrupts the communication between the grooves 10 and 19. Thereturn ducts 11 and 12 now are series-connected by the piston groove 10.The extent of delay of the closing movement is defined by thatthrottling element which has the more pronounced throttling action, i.e. by the throttling element 16. It has to be noted that, according tothe extent of such throttling, the door closing movement within the saidcertain door opening angle which corresponds to the positions of thepiston 2 in Figs. 2 and 3, may be delayed as desired, i. e. down tostandstill, in which case the throttling element 16 is entirely closed.When the piston 2 is positioned as shown in Fig. 4, i. e. when ituncovers the mouth of duct-end 11b, the displaced oil flows from thecylinder chamber 14 through the duct 11 directly into the forwardchamber 13 so that the door closing movement again is checked onlythrough the action of throttle element 15. In order to slightlyaccelerate the closing movement at the end of the piston stroke,

for the purpose of ensuring proper engagement of the door latch, thesaid groove 20 is provided in cylinder 1. When the piston 2 has attainedthe position shown in Fig. 5, the oil may escape from chamber 14 throughan additional passage past piston 2, namely through the longitudinalgroove 20, so that the door closing movement is checked to a lesserextent. When it is desired from any reason whatever to quickly close thedoor by hand, the pull exerted on the door by a person closing the door,causes the piston 2 to move faster, whereby the oil pressure in cylinderchamber 14 is raised. The increased oil pressure is propagated throughthe bore 17 and, overcoming the action of spring 21a, causes valve 18 toopen, whereby a direct passage of relatively large cross-section isproduced between the cylinder chambers 14 and 13. The door closingmovement thus is checked substantially less by the throttle elements 15and 16 respectively.

When opening the door, the excess pressure built up on the forwardpiston end face causes the ball 7 in piston 2 to leave its seat 8, theball 7 through the stop 9 being prevented from leaving the bore 6. Thusthere is provided direct communication between the cylinder chambers 13and 14 so that the piston 2 may be moved, and thus the door openedwithout encountering any appreciable checking action.

lt is to be noted that the range within which the piston will beadditionally checked through the throttling element 16, may correspondto any desired range of door opening angles. The arrangement suitablymay be such that the piston movement is additionally checked during thattime in which the displacement rate is a maximum andl, therefore, thecheck piston 2 is checked most effective y.

What I claim as new and desire to secure by Letters Patent is:

l. A door closer comprising a hydraulic checking device including acylinder and a piston therein, throttling means in said device forcontrolling the closing movement of the door, and a second throttlingmeans in said device for producing a throttling action limited to acertain range of the door closing movement, the throttling action ofsaid second throttling means being superposed to the throttling actionproduced by said first mentioned throttling means to provide for anunhindered passage through the door opening by an increased door brakingaction during said range of closing movement.

2. A door check comprising a hydraulic checking device including acylinder and a piston therein, a pair of throttle passages incommunication with said cylinder to by-pass fluid around said piston,said passages overlap- 301,883 3 4 ping with the outlet of one passageintermediate the inlet 3. A door check as defined in claim 2 wherein theand outlet of the other passage, said cylinder having a second of saidpassages is more restricted than the first groove in its wall extendingfrom the outlet of said other passage.

passage to a point adjacent said intermediate outlet of saggl onedpassage, and saic'l1 piston having a groove in its 5 References Cited inthe file of this patent w an operative as sai piston moves to successivey place said intermediate outlet in communication with said UNITEDSTATES PATENTS cylinder groove, whereby said passages are in parallel re1,848,371 Moore Mar. 8, 1932 lation, and to place said intermediateoutlet in communl- 2,116,185 Bernhard May 3, 1938 cation with said otherpassage inlet, whereby said passages 10 2,586,135 Woodruff Feb. 19, 1952are in series.

